.header {
    display: flex;
    width: 100%;
    height: 44px;
    position: fixed;
    top: 0;
    left: 0;
    z-index: 1000;
    background: #fff;
    .header_left {
        width: 44px;
        height: 44px;
        line-height: 56px;
        color: #666;
        text-align: center;
        align-items: center;
    }
    .header_center {
        flex: 1;
        justify-content: center;
        align-items: center;
        text-align: center;
        line-height: 44px;
        height: 44px;
        font-size: 18px;
    }
    .header_right {
        height: 44px;
        width: 44px;
    }
}